package com.dinner.util;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.FilterConfig;

public class SetCharacterEncodingFilter implements Filter {
	protected String encoding;
	protected FilterConfig filterConfig;
	protected boolean ignore;

	public SetCharacterEncodingFilter() {
		encoding = null;
		filterConfig = null;
		ignore = true;
	}

	public void destroy() {
		encoding = null;
		filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		if (ignore || request.getCharacterEncoding() == null) {
			String encoding = selectEncoding(request);
			if (encoding != null)
				request.setCharacterEncoding(encoding);
		}
		try{
			chain.doFilter(request, response);
		}catch(NullPointerException e){
			//do nothing
		}
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
		encoding = filterConfig.getInitParameter("encoding");
		String value = filterConfig.getInitParameter("ignore");
		if (value == null)
			ignore = true;
		else if (value.equalsIgnoreCase("true"))
			ignore = true;
		else if (value.equalsIgnoreCase("yes"))
			ignore = true;
		else
			ignore = false;
	}

	protected String selectEncoding(ServletRequest request) {
		return encoding;
	}
}